383 stroker will it work?????

[WELLCRAFT707]

im currently building a 383 stroker for my 1980 wellcraft sun hatch 196.
the boat came with a 898 mercruiser 305.
i was wondering will my drive take the 400 hp from the stroker motor or will i have to go with another drive like a bravo or somthing......

 

[jtybt]

Re: 383 stroker will it work?????

I had an MR/alpha behind my 406. crunched it twice...and I don't hot-rod.
The drive could have been stressed by PO but my motor didn't help.

Swapped to a BII. Nice and beefy!(boat weighs 7660 lbs)

 

[WELLCRAFT707]

Re: 383 stroker will it work?????

I had an MR/alpha behind my 406. crunched it twice...and I don't hot-rod.
The drive could have been stressed by PO but my motor didn't help.

Swapped to a BII. Nice and beefy!(boat weighs 7660 lbs)

thanks for that.... i just talked to a guy on youtube who build a 383 for his 23foot sea ray cabin cruiser and he still has the alpha drive from 1988 and he runs 60 mph with 490 dyno h.p. he said to not do any hard starts from a dead stop..... but ill see. if breaks it breaks.....

 

[Bondo]

Re: 383 stroker will it work?????

if breaks it breaks.....

Ayuh,... It will....

 

[Fun Times]

Re: 383 stroker will it work?????

I have seen some of the performance guys say heat is one of the weak links, And you should change your oil often, And no hard or fast take offs, Roll in to the throttle slowly And you might get lucky for awhile and then again you might not. It's like vagas baby 50/50 Good luck with it.

 

[wca_tim]

Re: 383 stroker will it work?????

Running an alpha drive... on a LIGHT boat

I snapped a lower drive shaft with a v-6...

"threw" a driveshaft / rear yoke behind a 383 (lost c-clip under power? couldn't tell from what was left after)...

have burnt up one set of upper gears with a 383...

Have several trashed alpha drives in the shop.

putting an alpha ss on this weekend and have a set of hardened, cryo-treated gears and bearings to put in once happy with set-up...

The other thing to consider is that for the cost of a bravo conversion, you can break and replace an alpha upper or lower half a dozen times.

heat is a potential issue, but running the exhaust through hull instead of through the drive can make a big difference there. The primary cause of drive failure is lack of propper maintenence - in any situation! I'm pretty sure that the burnt gears above really resulted from a leak.. lube out and / or water in.

the biggest issue is that with fairly small gears and bearings, not a very stiff housing relative to the horsepower / torque of a big block or stroked small block, and virtually zero lubrication circulation, an alpha type drive is a pretty much a consumable once you start pushing over 350 horsepower - especially if you've got a good bit of torque like a 383 will have.

the higher the gear ratio (more mechanical reduction, ie 1.81), the faster the boat will be so long as you don't go over 30 or so pitch props. With higher gear ratios, more of the torque loading is transfered to the lower gears (reduction is in the upper). The lower the gear ratio (less mechanical reduction, lower pitch props), the less torque loading the drive will see overall, however, the heavier torque loading will be on the upper gears... which more often go south under power than the lower gears. I have a feeling that this is why the 1.47 gear ratio is the standard gear for alpha drives behind v-8's. You can also get heavy duty gears for 1.5 and 1.32 ratios. as with any gear set-up cryo-treating them and the bearings will reduce friction and wear and help contact point heat issues.

Change and check lube often, use good synthetic lube. I've been running merc synthetic lube - good stuff, but am switching to redline heavy duty shockproof lube (solid suspension lube).

no matter what you do, if you stiff-arm the throttle out of the hole on a heavy boat (any boat), sooner or later you'll have a drive full of bits of metal and broken gears....

bottom line is it'll live... but keep a spare drive, you may need it.

ps. SEI will deliver gauranteed 2-day for an additional 70...

 

[Howard Sterndrive]

Re: 383 stroker will it work?????

you have the wrong gears in your 305 alpha drive.
With that drive and prop, you won't go any faster than you did with the 305.

You can reprop, but the torque going to the lower unit will be double what the drive can take.

your buddy with the SeaRay probably has a 1.32:1 drive and that's why it has survived this long.

 

[wca_tim]

Re: 383 stroker will it work?????

you have the wrong gears in your 305 alpha drive.
With that drive and prop, you won't go any faster than you did with the 305.

You can reprop, but the torque going to the lower unit will be double what the drive can take.

your buddy with the SeaRay probably has a 1.32:1 drive and that's why it has survived this long.

prop is wrong, but gears aren't wrong for speed... and since the upper gearset is usually what lets go under excessive power... it's probably not all bad to put more on the lower. there are a number of guys around here with really healthy small blocks in front of alpha drives... I know of at least one with a blower on a stroked small block...

build your stroker to be a little soft on the bottom end of the rpm range, make up for it on holeshot with gear ratio and it'll pul like now out of the hole and have a heck of a lot more midrange and top end. of course you're going to have to play with props no matter what you do...

 

[jtybt]

Re: 383 stroker will it work?????

The alpha is generally accepted to be rated at 300 HP.

Alphas have very anemic gears. If you've ever seen the alpha and bravo gears. you know what I mean.

One of the biggest causes of gear damage is the RPM during shifting. Always let the RPMs go down to idle before shifting. Idle should be 650 RPM.

 

[jaxnjil]

Re: 383 stroker will it work?????

do your self a favor and start with a bravo drive.

there is a very good reason searay and mercruiser only used this combination for a couple of years.

as far as the cost to just keep changing the alpha's because there cheaper than switching to bravo; having lunched 4 alpha drives i would have been better to have made the swap the first time i broke one. i got about 20 hr. each. they might be cheap but there not that cheap.

that doesn't include the problems you have when you lock up a drive on the lake. you cant put a price on being stranded. trust me cheap doesn't come into play when you blow a drive and your stuck in a 15 mph wind trying to keep off the rocks

 

[jaxnjil]

Re: 383 stroker will it work?????

thanks for that.... i just talked to a guy on youtube who build a 383 for his 23foot sea ray cabin cruiser and he still has the alpha drive from 1988 and he runs 60 mph with 490 dyno h.p. he said to not do any hard starts from a dead stop..... but ill see. if breaks it breaks.....
__________________

never broke a drive water skiing or wake boarding either
every one i broke was cruising 30 mph at 3000 or so rpm. twice the lake was glassed off and early in the morning; perfect conditions.

our boat went with the 1:32 to 1 drive for 15 years before the po started messing with swapping gears. then much SADNESS

 

[Howard Sterndrive]

Re: 383 stroker will it work?????

I have a couple of "1.32 gears discontinued... lets reprop it to compensate" horror stories too.

with 1.50 gears, you have way too little speed on the vertical shaft... all torque

and torque is what breaks things.

 

[HT32BSX115]

Re: 383 stroker will it work?????

I'm a little confused....


Why would someone build up a "rock'n roll" hot rod engine and then put it in front a drive that would prevent a "bugs in the teeth" run down the lake?

You might as well just put a 165 inline 6 in the boat!

 

[Utahboatnut]

Re: 383 stroker will it work?????

My last boat was an 84 196 sunhatch but it had the 235 outboard on it. I could get 45+ with the right prop and pull a couple of slalom skiers. With a 383 stroker that thing will fly(with the right drive) If $ permits I would go the bravo to start thus eliminating the "I hope the drive holds today" every time you go out. Piece of mind is worth a lot to me. Or at least have a kicker stowed away so you can get back when it cuts loose.

 

[Thad]

Re: 383 stroker will it work?????

Would you put a 700R behind that motor? No, you'd beef up a 350 turbo with a B&M shift kit.

So why would you ever even think about not putting a Bravo on there?

I know, brain fart, right?

Seriously, go with the bigger, better drive that can handle those ponies and let her run.

 

[wca_tim]

Re: 383 stroker will it work?????

for a small light boat an alpha is fine even "overpowered" - especially if that's what's there already. there's less power loss than a bravo, less wetted surface area and it's lighter... plus a ton cheaper. I prefaced my mess above by saying that I'm hard on things. the original upper drive that I finally burnt up this past month had a lot of hours running at 5000+ rpms, sometimes as high as 6000 rpms and help up for runs that were 10s of miles long at 5000 plus rpms (note that this is a 1.8 gear running around 28" 4 bladed props most of the time - plenty of torque loading on the drive). between that and pulling boarders, skiers and tubers much of the rest of the time, the upper gearset that was finally blued and burning the lube up (but didn't come apart), held up really well. and that's not a set of the heavy duty gears...

I have no doubt that if you take good care of an alpha drive, don't hammer the throttle or catch air, it'll last a good long time behind a relatively "mild" 383... worst case is you eventually break one... buy another used then pony up to do the bravo, sell the complete drive and transom assembly for a reasonable price...

I would not worry much about doing it and se what happens.

 

[WELLCRAFT707]

Re: 383 stroker will it work?????

for a small light boat an alpha is fine even "overpowered" - especially if that's what's there already. there's less power loss than a bravo, less wetted surface area and it's lighter... plus a ton cheaper. I prefaced my mess above by saying that I'm hard on things. the original upper drive that I finally burnt up this past month had a lot of hours running at 5000+ rpms, sometimes as high as 6000 rpms and help up for runs that were 10s of miles long at 5000 plus rpms (note that this is a 1.8 gear running around 28" 4 bladed props most of the time - plenty of torque loading on the drive). between that and pulling boarders, skiers and tubers much of the rest of the time, the upper gearset that was finally blued and burning the lube up (but didn't come apart), held up really well. and that's not a set of the heavy duty gears...

I have no doubt that if you take good care of an alpha drive, don't hammer the throttle or catch air, it'll last a good long time behind a relatively "mild" 383... worst case is you eventually break one... buy another used then pony up to do the bravo, sell the complete drive and transom assembly for a reasonable price...

I would not worry much about doing it and se what happens.

thanks man i think im just gone try it first with the alpha and i talked to a friend of mine and he told me 350 h.p. would take that wellcraft to 60 with no problem but i am going to run thru hull exhuast . but im pricing bravo drives and transom housings now